LondonOrigami

Recommended Origami Books

Review of:

The Silver Rectangle

British Origami Society (BOS) Booklet 21

First Published by BOS 1983

Reprinted 2008

Revised Edition 2015

Reviewer: Arnold Tubis

In mathematics, the silver ratio is defined as [1+ square root (2)]/1, or approximately 2.414, but in the world of paper shapes, the silver rectangle has a length/width (aspect) ratio of [square root (2)]/1, or approximately 1.414. In the words of author John Cunliffe, “the longer side is equal to the diagonal of a square whose side is the same as the length of the shorter side.” The hallmark of the silver-rectangle shape is that if the paper is creased after the two short sides are brought together, another (smaller) silver rectangle is formed.

Outside of North America, the A, B, C standard stationary paper sizes all refer to the silver rectangle shape. In North America, the rectangular aspect ratio 11/8.5 is the norm for the most common stationary paper shapes.

After a clear summary of methods for forming silver rectangle shapes from squares and other rectangular shapes and dividing them into thirds, this little booklet contains steps for folding twenty-two simple silver rectangle forms. (The steps are much clearer in the revised edition mainly because of the extra shading in the drawings.) The folded forms include an arrow, various containers, a letter fold, a napkin fold, a cap, and geometric shapes (square, equilateral triangle, regular hexagon, pentagon, and pentagram). It should be mentioned, however, that many of these forms could just as well be folded from paper with other than silver-rectangle shapes.

With regard to the geometric shapes, the pentagram (five-pointed star) shape (page 26) is irregular, in contrast to the regular pentagram that for example characterizes the stars on he American flag. I found it interesting to see how easily the outline of an approximate regular-pentagon shape could be formed (page 27). According to the folding sequence, it is easy to see that the internal angle at the apex has a measure of around 109.43 degrees instead of 108 degrees in the case of a regular pentagon.

As it stands, this booklet constitutes a nice concise introduction to the silver rectangle in origami. However, I would have liked to see more contemporary references to artistic origami that exploit the properties of this unique shape. The author does mention the pioneering book of E. Nakamura (1972), and works of S. Fujimoto, but (perhaps in future revisions) should also bring attention to the beautiful book, now accessible in English: Jun Maekawa, Genuine Japanese Origami/ 33 Mathematical Models Based Upon the Square Root of 2 (Dover Publications, New York, 2012), and references therein to related works by K. Kasahara, K. Ohashi, and others on silver-rectangle models.

ebook versions

£1.99

£4.50

£4.00

£4.00

£4.50

£4.00

Interactive ebook (Apple ibook format only)

FREE

Includes interview with

Rikki Donachie

ebooks are in pdf format

BOS Imprint - selected printed books

£4.50

£4.50

£6.50

£6.50

£5.50

£7.50

£5.50

£8.00

£6.50

£4.50

£6.00

£6.00

£6.00

Offers:

Books available from Amazon have free postage for orders over £10.00 in the UK.

Books available from BOS Imprint have free postage for orders over £50.00 in the UK.

ebooks and BOS Imprint have 10% discount for members of the British Origami Society.

£4.50

£4.50

FREE Educational books

FREE Theoretical books

£4.00

Reviews

£4.00